PRIOR CONCURRENT THERAPY: See Disease Characteristics Biologic therapy: More than 1 month since prior biologic therapy or immunotherapy Chemotherapy: More than 1 month since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) Endocrine therapy: At least 4 weeks since prior steroid therapy or steroid-containing compounds At least 2 weeks since prior topical or inhaled steroids No concurrent steroids Radiotherapy: More than 1 month since prior radiotherapy, interstitial brachytherapy, or radiosurgery Surgery: Not specified